In recent years, with the various purposes including that of improving the productivity of photographic prints, a rapid color processing has been strongly demanaded and the various measures therefor have been taken. As one of the measures, it has been known that a color development accelerator is used when an exposed silver halide photographic light-sensitive material is developed by making use of an aromatic primary amine type color developing agent. As for the color development accelerators, there have been studied on the compounds including, for example, those described in U.S. Pat. Nos. 2,950,970, 2,515,147, 2,496,903, 4,038,075 and 4,119,462; British Pat. Nos. 1,430,998 and 1,455,413; Japanese Patent Publication Open to Public Inspection (hereinafter called Japanese Patent O.P.I. Publication) Nos. 15831-1978, 62450-1980, 62451-1980, 62452-1980, 62453-1980 and 12422-1976; Japanese Patent Publications Nos. 12422-1976 and 49728-1980; and so forth. However, most of the compounds have displayed unsatisfactory development acceleration effect. Among them, even the compounds having displayed the satisfactory development acceleration effect have not been practically applicable, because they have been so defective that fog has often been produced.
For the purpose of accelerating the permeation of a color developing agent into a silver halide light-sensitive material, various types of permeating agents have been studied. Among them, for example, there has popularly been used a method that benzyl alcohol is added to a color developer to accelerate a color development.
In this method, however, a satisfactorily high color density cannot be obtained, unless a processing is carried out for three minutes or longer at a processing temperature of 33.degree. C., for example. Therefore, this method has, more or less, a fault from the viewpoint of rapid processability. There has also been proposed a color developing method in which a pH value of a color developer as well as a processing temperature are made higher. However, this method has some problems that, for example, the oxidation of a color developing agent is seriously accelerated when the pH thereof is raised to 10.5 or higher; a pH of a color developing agent is apt to be varied, because there is not any suitable buffer; stable photographic characteristics are, therefore, difficult to obtain; and the dependence on processing time may become greater.
On the other hand, for the purpose of making a color development more rapid, there has also been known a method in which a color developing agent is incorporated in advance into a light-sensitive material, as described in, for example, U.S. Pat. No. 3,719,492.
However, this method has defects that the raw stock stability of a silver halide photographic light-sensitive material is poor; fog is produced before using it; and fog is apt to be produced also in color developing process.
Besides the above methods, for the purpose of making inert the amine portion of the color developing agent, there is, for example, a method of incorporating the color developing agent which was made in the form of a Schiff base. This method is described in, for example, U.S. Pat. No. 3,342,559 and Research Disclosure, 1976, No. 15159. In these methods, however, a color development is not started unless the alkali-hydrolysis of the color developing agent is completed, and therefore these methods have a defect that the color development becomes rather in delay.
Japanese Patent O.P.I. Publication No. 64339-1981 discloses a method of adding 1-aryl-3-pyrazolidone having a specific structure into a silver halide color photographic light-sensitive material; and Japanese Patent O.P.I. Publication Nos. 144547-1982, 50532-1983, 50533-1983, 50534-1983, 50535-1983 and 50536-1983 each disclose the methods of adding, in advance, 1-arylpyrazolidones into a silver halide color photographic light-sensitive material and processing the light-sensitive material within a very short developing time.
However, from the viewpoint of obtaining both of a satisfactorily high color developing rate and a high color density dye-image, the techniques disclosed in the above-given specifications cannot always be satisfactory, but there are rooms for improvements.
In recent years, it has been known that a silver chloride emulsion or a silver chlorobromide emulsion having a high silver chloride content is used as a silver halide emulsion with the purpose of making a color development faster. These techniques are described in, for example, U.S. Pat. Nos. 4,183,756 and 4,225,666; Japanese Patent O.P.I. Publication Nos. 26589-1980, 91444-1983, 95339-1983, 94340-1983, 95736-1983, 106538-1983, 107531-1983, 107532-1983, 107533-1983, 108533-1983 and 125612-1983; and so forth.
The techniques described in the above patent specifications are reasonably satisfactory from the viewpoint of rapid processability and superior to the various types of rapid processing means aforementioned. They are still not satisfactory for making sensitivity faster and, further, have such a problem that the sensitivity variation thereof is serious to a change on standing particularly in preparing a light-sensitive material.
When a silver halide photographic light-sensitive material is prepared, a coating liquid for a silver halide emulsion (hereinafter called a coating liquid) is prepared in such a manner, ordinarily, that silver halide grains which were spectrally sensitized and chemically ripened are mixed together with various additives such as a binder, a surafce active agent, a hardener, a coupler, a mordant and so forth. It is well-known that a silver halide photographic light-sensitive material is completed by coating the coating liquid over to a support in various methods and then by drying it.
Upon preparation of the above-mentioned coating liquid, it is coated at a certain temperature after a lapse of several hours to some tens of hours. During that period of time, the quality of the resulted silver halide photographic light-sensitive material should constantly be stable. However, a silver halide emulsion having a high silver chloride content has a serious obstacle for practical use, because the sensitivity thereof is seriously varied with a lapse of aging time of a prepared coating liquid, as compared to the conventional silver halide emulsions having a high silver bromide.
With the purposes of preventing the characteristics, including particularly the sensitivity, of the above-mentioned coating liquid from varying during the storage, there have been proposed the measures such as; a method of adding an azole, an azaindene or the like which have been well-known as stabilizers; a method of adding such a reducing agent as a hydroquinone, a sulfinic acid or the like; a method of jointly using a specific copolymer and an optical brightening agent, as described in Japanese Patent O.P.I. Publication No. 111629-1974; a method of adding a spectral sensitizing dye as described in Japanese Patent O.P.I. Publication No. 7629-1983; a method in which a water-soluble bromide is added into a coating liquid so as to prevent a spectral sensitizing dye from desorbing in the coating liquid, as described in Japanese Patent O.P.I. Publication No. 28738-1983; and so forth. None of the above-given methods may be able to display any good effects and satisfy any characteristic requirements.
The inventors have devoted themselves to solve the above-mentioned problems and have resultingly found the unexpected fact that a coating liquid is prepared in such a manner that a specific high silver chloride containing emulsion is chemically ripened and a specific amount of a water-soluble bromide is then added thereto and further a coupler is dispersed therein by making use of a specific high boiling organic solvent, and the resulted coating liquid is used to prepared a silver halide photographic light-sensitive material which is high in sensitivity, excellent in rapid processability and less in sensitivity variation to a change on standing in the course of preparing the light-sensitive material. Thus, the inventors have been able to achieve the invention.